Process of simultaneously volatilizing phosphorus and producing latent hydraulic binders



'Patented Octfi, 15931 I PATENT OFFICE GirsfrAv rrsron, or rnirzlrdnnn nosnar-suciixenn EMIL REUBKE, or BITTERFELD, G BM NY, ASSIGNORS no I. rnnnnn nnusrmn AKTIENGESELLSCHAFT, or rnenKroar-omTHn-rmm;GERMANY, A ,GORPORATION or GERMANY rno'onssor sIMUL'rAnnoUsLY 'HYnnAULIoBInDnRs VOLATILIZING PH OSPHOBUS AND PRODUCING LATENT No' Drawing. Application filed February 10, 1 928,S erial No. 253,51 6, and in Germany February 10, 1927.

This invention relates tothe simulta neoi 1 s production of phosphorus or phosphoric acid.

andlatentdiydraulic binders. It has been re-Q I peatedly proposed in the thermic production of phosphorus or phosphoric acid to substitutefaluminous substances for the usually added silicic acid, in order to obtain slags having hydraulic properties'enabling them to be used without further modilicatignlas hydraulic cements However, when in'this I "ca'sethe ratio of raw. materials is adjusted;so

V i s as to yield a slag resembling in composition a Portland cement clinker, the required high contents of lime (from,62 65% );iprove to-be an obstacle n carry ng out this process, as -a' certain amount of calc um carbide 1s s multaneously produced which forms amost un desirable contamination of the slagproduct.

Now we have found that such difiiculty does not arise when the furnacecharge is composed in such a manner that when treating phos phates in which the phosphoric acid is com- 7 binedwith lime-oralumina 1 about 16.5 to 18.7% A120 30.8 to 33.5% SiO 1 with carbon sufficientto reducethe pentoxide of phosphorus and with the additions of the aluminousor silicious materialv required, a slag containing and 40-to50% CaO' is obtained. By melting down a mixture of this composition the ph'os v phorus is completelyvolatilized and a slag is obtained forming, after granulation, a latenthydraulic binder and excellently. suitable for making blast-furnace cements. As an advantage of this process, as compared with the production of a slag immediately suitable as a Portland cement, it has; been'recognized that it is no longer necessary to endeavor to obtain an absolutely uniform CODJPOSltlOIl of j the slag, so that a'certain amount of variation 9 inthe composition'of the charge will do no harm,'as the ratio between silicic acid and alumina may be variedwithin wider limits than is consistent with the immediate production of Portland Cement.

The process may be carried out continuously either in an electric or in a shaftfurnace, carbon serving as a reducing agent and in the latter case the quantity of carbon being correspondingly increased at the same time, the surplus servingfor the generation of the heat requiredin carrying out the process. In this caseanexcess in air-blast will cause also phosphoricacid to be present in the gaseous products besides phosphorus.

The resulting slag is ground in the well- .fofthe s'la'g. The important economic and technical advantages of the invention also -'2 tpp'ea r in comparison with the blast-furnace process, in which the composition of the slag is determined by thequality of the minerals employed and the' quality of the iron produced in'the blast-furnace.

7 Examples 1. 100 parts of a raw phosphate containing are melted in an electric furnace with parts of clay containing 56% SiO and 32% A1 0 and with Qtparts of a well dried coke to produce phosphorus. The same quantities of said raw-materials, mixed with a further quantity of 80 parts of coke'for'heating the charge, are to be employed when the process "shall be performed on an air blast shaft furnace'to produce phosphorus and phosphoric acid. A slag is obtained composed of about 50% GaO,'18% A1 0 and 32% SiO which is excellently suitable for making a blastfurnace cement by being ground together with afortland cement clinker.

18% ril O g a-nd' 32% S10 having excellent hydraulic propertiesfis tapped off from time to time.

l l8r parts ofamixture of frawyphos- 'phates,'-containing 50 parts QaO, 10.5,parts r Al O 22 parts SiO and48parts P with 18.3'parts'o f clay containing 63% SiOa and 7 28 %"Ai Ug and with-4O part-sot coke arev gtreated' as described in example 2; the result fling slagcontains 50% CaO 16.5% A1 0,,

8 and ("$3.57 SiO and" is" likewise ez lcellently Kits 7 p mate, (for instance Saldana j phos re airer making]a ..blastfurnace cementg v41"., Ainixtureof 1614'partslof'a'naluminum irl in e .e .7

" phate) containing 23.4%Al O 39.8%

and 30,5 P O ',;with105,parts of a calcium phosphate;"containing e7.3%1 CaO, 0;7%

501:8 is'continujously introduced into a hos phorus "furnace and, melted down: A liquid slagresults composed'off30.18% Si O 1{8f.7% AlgOgflnd 50% C210; VWhereas, in the'manugf nature; of phosphorus according to-'-'processes o theold art, about 8 kilograms of slag'are I SiO and- 4O to 50% C510;

' 7 formed per l kilogram of phosphorus, only aboutI l kilograms of slag having the quality 7 of a letent' hydra'ulic binder. are obtained according to our'rne'thod of 'oper'atingwhereby' animp ortant saving of'energy'isinvolved.

' It'h'as already been proposedtosplit bfi:

phosphorus pento xid'e from a mixture of Cale cites and; aluminum-phosphates calcin-: ingfthe same I at temperaturesbelow' the 'rnelt- "lingpoint the reaction product. This meth odfhoweyer, has not produced satisfactory results, considerable ,portionsbf the phosphates-remaining undecompose'd, as-aSc ci -j x v ,e v

T1 ;wh1ch compr ses, melting in the presence of tained by experiments-.1

"1., AI-process :for simultaneously IVo1atiliz-.

phosphorusandproducing a slag having the properties oi a latent hydraulic binder;

1 fwhichacomprises-r melting in the presence of a tens mixture of apho'sphate containing 7 lsilicoii dioxide and calcium oxide; with an aluminous material, at least a .part of; the

aluminium contents of said material being co mbined fw'ith phosphorus oxide and 1 the totalamounts of the calcium oxide, alumin- 7 ium "oxide and silicon dioxide'fcontents of constitute atter elimination of" the phorus a slag containing about-16,5 to18.7% of aluminium oxide, f

'aluminous materiahoiie part of the alumin ium content of the said materialbeing combined with phosphorusoxide and another partcombinedwith' silicon dioxide, the/total" amounts of the calcium oxide," aluminium *bxideand silicon dioxidev contents of said 1 mixture being in such proportions as to conj stitute" after elimination of the phosphorus a slag containing. aluminiuinioxide, silicon dioxide and calcium oxide in the proportions of about 16;5.t0 18.7%,Al O 30.8 to 33.5%

'SiO and 40m CaO.

3. A'process of simultaneously volatilizing phosphorus and producing a slag having the" properties of latent hydraulic binder, which comprises melting in the presence' of carbon amixture' of I aphosphate containing silicon dioxide and-calcium oxide with an aluminium phosphate, further a 'quantityof clay, also a jfquantity of'lbauxite", thetotal "amounts of the calcium' oxide, aluminium oxide andsilicon dioxide contents ofthe said mixture being in such proportions as to con-e oxide and calcium ox'idein the proportions ofiabout- 16J5' mi-18.7% A1gO 30.8 "to 33.5% p

. f4; A process of siin ltaneously volatilizing phosphorus and producing a slag havingthe 'properties'of alatent hydraulic-binder, which comprises melting a mixture 'of about 76% parts of an aluminium phosphate containing A1203 and i with 105 parts of-a calcium phosphateconta1ning,47.3% CaO, 0.7%x SiOQan'd 35.1% P 05, with 41 parts of coke.

' 5, Aprocess for sim ltaneously yolatilizing phosphorus and producin'ga slag having the proprties'bf a latent hydraulic binder,

carbona mixture of a -phosphate containing silicon dioxide and calcium oxide with an 'aluminous' material; at least} a' part of the aluminium contents of said material being combinedfwith phosphorus oxide and the total amounts of the 'calciumoxideg, aluminium oxideand silicon dioxide contents of said'mixtu're being in such-proportions as to phos- In testimonyfwhereof we have hereunto se't our hands.

' GUSTAV PisroR},

' ROBERT SUOHY. i

" EMI-L meme 1 "2.,A1process for, simultaneously volatiliz 1:1

phosphorusand producing a slag having "the properties of a'latent hydraulic-binder,

' i so I 

